Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
A cellular wireless network may include a number of base stations that radiate to define wireless coverage areas, such as cells and cell sectors, in which user equipment devices (UEs) such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly equipped communication devices, can operate. In turn, each base station may be coupled with network infrastructure, such as a mobile switching center (MSC) and/or a packet data serving node (PDSN) for instance, that provides connectivity with one or more transport networks, such as the public switched telephone network (PSTN) and/or a packet-switched network such as the Internet for instance. With this arrangement, a UE within coverage of the network may engage in communication with a base station over an “air interface,” and may thereby communicate via the base station with various remote network entities or with other UEs.
In addition to such components as antennas and transceivers that provide radio frequency (RF) access, base stations may include or be communicatively coupled with other components and/or devices for controlling and managing RF communications, and interconnecting with each other and with network transport and network core functionalities. Functioning collectively to provide wireless (i.e., RF) access to services and transport in the wireless communication system, these components and devices (e.g., base stations, MSCs, controlling entities, etc.) comprise what is typically referred as a Radio Access Network (RAN).
In an example arrangement, the network infrastructure may include one or more gateways or similar components that provide connectivity with a packet-switched network so as to support various communication services. For instance, the infrastructure may include gateways that support general packet-data communications, such as general web browsing, file transfer, and the like. Further, the infrastructure may include gateways that support real-time packet-based communications such as voice over Internet Protocol (VoIP) and streaming media for instance, by exchanging communications with one or more application servers that provide such services. And still further, the infrastructure may include gateways that support other types of communication services as well, possibly arranged to exchange communications with other types of application servers and systems.
When a UE powers on or moves into the coverage of a base station, the UE engages in a process of registering or “attaching” with the network, which triggers setup of various communication channels for the UE. For example, in a network operating according to the Long Term Evolution (LTE) protocol, a UE transmits an attach request message to the base station, which the base station forwards to a controller such as a mobility management entity (MME). In response, the controller then invokes a process to authenticate and authorize the UE and retrieves a service profile of the UE from a subscription database and stores them for later reference during service invocation to determine one or more services that the UE is authorized to use. Further, the controller engages in signaling with the base station and one or more gateways to define one or more bearer connections for the UE between the base station and the gateways. The base station may then assign a radio link layer connection for the UE. And to the extent the gateways support communication with particular servers or systems, the gateways may then further register with those servers or systems on behalf of the UE.
Once these connections are established, the UE may then be considered as engaging in a communication session, during which it may communicate bearer data (e.g., application layer communications such as web browsing and VoIP setup signaling and traffic) with various application servers or systems. In particular, as the base station serves the UE in the communication session, bearer data may pass from the UE over the radio link layer connection to the base station, through one or more bearer connections between the base station and one or more gateways, and from the one or more gateways onto the packet-switched network and perhaps to particular application servers or systems. Likewise, communications destined to the UE from various application servers or system may pass to the one or more gateways registered on behalf of the UE, then over one or more bearer connections from the one or more gateways to the serving base station, and over the radio link layer connection from the base station to the UE.